Frame for pistol with removable metal rail

ABSTRACT

The present invention relates to a frame for a pistol with a removable metal rail, in which a pistol has a slide made of a plastic material, and which is capable of preventing the gap between the slide and the rail of the frame from occurring due to thermal deformation, and separately disassembling the frame unit and the rail of the frame from each other to replace them as occasion demands. 
     According to an aspect of the invention to achieve the object described above, there is provided a frame for a pistol with a removable metal rail, a pistol having a slide made of a reinforced plastic material, the frame including: a frame unit made of a metal material and having a handle and first and second insertion parts formed at its upper portion, the first and second insertion parts being spaced at a predetermined distance from each other; and front and rear rail blocks made of a metal material and fixedly inserted into the respective first and second insertion parts, the slide being slidably assembled to both upper sides of the front and rear rail blocks, wherein: the first insertion part has an insertion groove having a predetermined depth, the insertion groove having a fastening hole formed through both sides thereof; and the front rail block has an insertion protrusion protruding downward from its bottom surface by a predetermined length such that the insertion protrusion is inserted into the insertion groove, the insertion protrusion having a through-hole formed through both sides thereof to communicate with the fastening hole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Korean Patent Application NO 10-2017-0154801 filed on Nov. 20, 2017 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a frame for a pistol with a removable metal rail, and more particularly, to a frame for a pistol with a removable metal rail, which is positioned at the lower portion of a slide made of reinforced plastic material, to be assembled to the slide.

Description of the Related Art

In a glock pistol, the components thereof such as a slide, a lower gun body, and a magazine etc., which are not directly associated with the discharge of bullets, are made of light reinforced synthetic plastic materials having a stiffness similar to a metal, so that it reduces the weight of the pistol and is easy to carry.

However, if the slide and the lower gun body etc. made of the reinforced synthetic plastic materials are kept at a higher temperature for a long time, as though it has an excellent stiffness plastic, the shapes thereof are deformed more or less and gaps between the assembled internal parts are generated.

In particular, the thermal deformation of the lower gun body made of plastic materials causes malfunctions and functionality failures between various components assembled to the lower gun body. As a result, it can deteriorate the shooting accuracy of the gun and the operation reliability thereof. Also, since it can cause the shooting accident etc. owing to the unnecessary gaps between the components, the safety of using the gun can be also deteriorated.

Therefore, recently, a metal part is added to the lower gun body of the glock pistol or it suggests a method of replacing the plastic lower gun body with the metal one.

As the conventional techniques for the above purposes, U.S. Pat. No. No. 6,260,301 (Title: Pistol whose housing is composed of plastic) and US publication No. 2009-0071053(Title: Modular firearm system with interchangeable grip and slide assemblies and an improved firing pin safety for firearm) have been disclosed. In the pistol (firearm) disclosed in the patent literatures, a metallic part (hereinafter called as ‘metal insert’) is attachably and deattachably inserted into the lower gun body made of the plastic materials and the trigger and the safety pin etc. are assembled by the metal insert. As a result, it is characterized in that the assembling status of the trigger and the safety pin etc. can be maintained under high temperature.

However, since the metal insert disclosed in the above patent literatures is manufactured by pressing and bending a thin sheet, it is not easy to manufacture the component having a fine machining tolerance owing to the manufacturing characteristic thereof. Therefore, since the gap between the lower gun body (gun body frame) and the metal insert is generated, the vibration and the noise are generated during firing of the bullet, thereby deteriorating the shooting accuracy thereof due to the vibration.

In addition, in order to solve the above problem, there is a method in that the entire lower gun body is made of the metallic materials. In this case, when the bullets are continuously fired or it is used in a high temperature environment, since a high-temperature heat is transmitted to the gripping portion for gripping the pistol by means of the user, it has trouble in using the pistol.

Accordingly, it requires the development of the frame for a polymeric pistol, capable of securing the structural soundness of firearms to secure an accuracy rate of bullet even in high-temperature environments, maintaining performance thereof for a long time without the deformation of the components, preventing the high-temperature heat generated in a barrel or the like from being transferred, as it is, to a handle of the frame, and disassembling and replacing components as occasion demands.

PATENT LITERATURE

Patent Literature 1: U.S. Pat. No. 5,655,326 B1 (Aug. 12, 1997)

Patent Literature 2: U.S. Pat. No. 6,993,864 B1 (Feb. 7, 2006)

Patent Literature 3: U.S. Pat. No. 8,156,677 B1 (Apr. 17, 2012)

Patent Literature 4: US 2014-0007479 A1 (Jan. 9, 2014)

Patent Literature 5: US 2009-0071053 A1 (Mar. 19, 2009)

SUMMARY OF THE INVENTION

The present invention has been made in view of the problem of the above-mentioned conventional plastic pistol, and an object thereof is to provide a frame for a pistol with a removable metal rail, in which a pistol has a slide made of a plastic material, and which is capable of preventing the gap between the slide and the rail of the frame from occurring due to thermal deformation, and separately disassembling the frame unit and the rail of the frame from each other to replace them as occasion demands.

According to an aspect of the invention to achieve the object described above, there is provided a frame for a pistol with a removable metal rail, a pistol having a slide made of a reinforced plastic material, the frame including: a frame unit made of a metal material and having a handle and first and second insertion parts formed at its upper portion, the first and second insertion parts being spaced at a predetermined distance from each other; and front and rear rail blocks made of a metal material and fixedly inserted into the respective first and second insertion parts, the slide being slidably assembled to both upper sides of the front and rear rail blocks, wherein: the first insertion part has an insertion groove having a predetermined depth, the insertion groove having a fastening hole formed through both sides thereof; and the front rail block has an insertion protrusion protruding downward from its bottom surface by a predetermined length such that the insertion protrusion is inserted into the insertion groove, the insertion protrusion having a through-hole formed through both sides thereof to communicate with the fastening hole.

Preferably, the second insertion part includes: an inclined contact portion that is inclined at a predetermined angle; a horizontal contact portion that is spaced rearward at a predetermined distance from the inclined contact portion and has a horizontal surface; a curved portion, the upper end of which is connected to the horizontal contact portion while the other end thereof is curved downward in an arc form; and a vertical contact portion having a vertical surface while the upper end thereof is connected to the lower end of the curved portion wherein: a pair of pin coupling holes is formed through both sides of the second insertion part between the inclined contact portion and the vertical contact portion and between the inclined contact portion and the curved portion, respectively.

Preferably, the rear rail block includes: a first contact part that is inclined to come into surface contact with of the inclined contact portion of the second insertion part while the rear rail block (20) is inserted into the second insertion part; a rear support part that has a second contact part formed at the bottom surface thereof to come into surface contact with the horizontal contact portion; a connection portion having an arc shape that is spaced at a predetermined distance from the curved portion; a third contact part that comes into surface contact with the vertical contact portion while the upper end thereof is connected to the lower end of the connection portion; and a pair of rear rails that protrudes from both sides of the rear rail block in opposite directions in the upper portion between the first contact part and the rear support part, and each of the rear rails has a horizontal length.

Preferably, the front rail block includes: a front support part that has a vertical surface coming into surface contact with the inside front of the first insertion part; a rear support part that has an inclined surface while coming into contact with the inside rear of the first insertion part; a pair of front rails that protrudes from both sides of the front rail block in opposite directions in the upper portion between the front support part and the rear support part and each of the front rails has a horizontal length; a slide lock through-hole that is formed through the side surfaces between the rear support part and the front rails so that the slide lock is inserted and installed in the slide lock through-hole; and a recoil spring installation groove having a predetermined depth that is formed between the pair of the front rails.

Preferably, the front rail block and the rear rail block are made of an aluminum material.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating an example of a frame for a pistol with a removable metal rail according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view illustrating an example in which a frame for a pistol, a front rail block, and a rear rail block according to an embodiment of the present invention are separated from each other;

FIG. 3 is a perspective view illustrating an example of the frame according to an embodiment of the present invention;

FIG. 4 is a top view of FIG. 3;

FIG. 5 is a sectional view illustrating an example of another frame according to an embodiment of the present invention;

FIG. 6A is a perspective view illustrating a front side of the front rail block according to an embodiment of the present invention;

FIG. 6B is a perspective view illustrating a rear side of the front rail block according to an embodiment of the present invention;

FIG. 7A is a plan view of FIG. 6A;

FIG. 7B is a side view of FIG. 6A;

FIG. 8A is a perspective view illustrating an example of another rear rail block according to an embodiment of the present invention;

FIG. 8B is a side view of FIG. 8A;

FIG. 9 is a cross-sectional view illustrating an example in which the frame for a pistol, the front rail block, and the rear rail block are assembled to each other according to an embodiment of the present invention; and

FIG. 10 is a view illustrating a state of use in an example in which a slide is assembled by the front rail block and the rear rail block according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, preferred embodiments of the invention will be described in more detail with reference to the accompanying drawings. The present invention is to provide a frame for a pistol with a removable metal rail, in which a pistol has a slide made of a plastic material, and which is capable of preventing the gap between the slide and the rail of the frame from occurring due to thermal deformation, and separately disassembling the frame unit and the rail of the frame from each other to replace them as occasion demands. As illustrated in FIGS. 1 and 2, a frame (2) according to an embodiment of the present invention includes a frame unit (10), a front rail block (20), and a rear rail block (30).

The frame unit (10) has a handle that allows a user to grip a pistol, and is configured such that a magazine is inserted through the bottom surface of the handle to supply bullets stored in the magazine toward the upper portion of the frame unit (10).

As illustrated in FIGS. 3 and 4, the frame unit (10) includes a first insertion part (11) and a second insertion part (12) which are formed at the upper portion thereof and are spaced at a predetermined distance from each other. The front rail block (20) is inserted and installed in the first insertion part (11) and the rear rail block (30) is inserted and installed in the second insertion part (12), which will be described later.

The frame unit (10) includes a magazine insertion part (13) that is formed between the first insertion part (11) and the second insertion part (12) to vertically communicate along the handle. The magazine insertion part (13) has an installation hole (13A) formed through one surface thereof. A magazine catch (not shown) is installed in the installation hole (13A) to be elastically supported by springs so that the magazine (not shown) inserted through the magazine insertion part (13) is restricted or the restriction thereof is released.

In addition, the first insertion part (11) is formed by forming a groove having a predetermined depth in the upper portion of the frame unit (10). As illustrated in FIGS. 4 and 5, the first insertion part (11) includes a front support protrusion (11A) that has a vertically stepped shape to support the front of the front rail block (20), which will be described later, and a pair of rear support protrusions (11B) that are spaced rearward at a predetermined distance from the front support protrusion (11A) and protrude from both sides of the first insertion part while facing each other to support the rear side surfaces of the front rail block (20).

The first insertion part (11) has an insertion groove (11C) formed on the bottom thereof, and the insertion groove (11C) has a predetermined depth while having a spherical, cylindrical, or square sectional shape. The insertion groove (11C) has a fastening hole (11C′) formed through both sides thereof.

Furthermore, a slide lock installation hole (11D) is formed through both sides of the frame unit between the front support protrusion (11A) and the rear support protrusions (11B) and a slide lock (not shown) is installed in the slide lock installation hole (11D) to restrict the sliding of a slide (2) or release the restriction thereof.

When the front rail block (20) to be described later is inserted into the first insertion part (11) by the structure of the first insertion part (11), the movement of the front rail block (20) is suppressed while the position of the front rail block (20) is naturally fixed by the front and rear support protrusions (11A and 11B). At the same time, the front rail block (20) is strongly fixed to the first insertion part (11) by a screw or a bolt (or a fastening pin) assembled through the fastening hole (11C′), thereby preventing the arbitrary separation of the front rail block (20).

Meanwhile, the second insertion part (12) is positioned in the rear of the frame unit (10) and is formed by forming a groove having a predetermined depth in the upper portion of the frame unit (10), as in the first insertion part (11).

As illustrated in FIG. 5, the second insertion part (12) includes an inclined contact portion (12A) that is inclined at a predetermined angle, a horizontal contact portion (12B) that is spaced rearward at a predetermined distance from the inclined contact portion (12A) and has a horizontal surface, a curved portion (12C), the upper end of which is connected to the horizontal contact portion (12B) while the other end thereof is curved downward in an arc form, and a vertical contact portion (12D) having a vertical surface while the upper end thereof is connected to the lower end of the curved portion (12C).

A pair of pin coupling holes (H1 and H2) is formed through both sides of the second insertion part between the inclined contact portion (12A) and the vertical contact portion (12D) and between the inclined contact portion (12A) and the curved portion (12C), respectively.

By the structure of the second insertion part (12), the rear rail block (30) to be described later is installed to simultaneously come into contact with three surfaces of the inclined contact portion (12A), the horizontal contact portion (12B), and the vertical contact portion (12D). Thus, the rear rail block (30) is inserted into the second insertion part (12) while being tightly supported by the three surfaces of the second insertion part 12, thereby allowing the position of the rear rail block to be fixed.

The front rail block (20) made of a metal material is installed in the first insertion part (11) of the frame unit (10), and the front bottom surface of the slide (2) made of a reinforced plastic material is slidably assembled by the front rail block (20).

As illustrated in FIGS. 6A and 6B, the front rail block (20) has front and rear support parts (21 and 22) that are respectively formed on one surface and the other surface thereof by cutting a rectangular material. The first support part (21) has a vertical surface coming into surface contact with the inside front of the first insertion part (11), and the rear support part (22) has an inclined surface while coming into contact with the inside rear of the first insertion part (11).

A pair of front rails (23) protrudes from both sides of the front rail block in opposite directions (more specifically, toward outside sides) in the upper portion between the front support part (21) and the rear support part (22), and each of the front rails (23) has a horizontal length. A slide lock through-hole (24) is famed through the side surfaces between the rear support part (22) and the front rails (23) so that the slide lock is inserted and installed in the slide lock through-hole (24).

In addition, as illustrated in FIG. 7A, a recoil spring installation groove (25) having a predetermined depth is formed between the pair of the front rails (23) so that one end of a recoil spring (not shown) for recharging the slide is inserted into and supported by the recoil spring installation groove (25). First and second slide lock support protrusions (24A and 24B) are formed in the recoil spring installation groove (25), and extend from the slide lock through-hole (24) to respectively support both sides of the slide lock. Guide grooves (24A′ and 24B′) are respectively formed in the middle portions of the slide lock support protrusions (24A and 24B), and the certain widths of the guide grooves (24A′ and 24B′) are partially cut such that one end of a lock spring is inserted into and guided by the guide grooves (24A′ and 24B′).

The recoil spring installation groove (25) has a mounting groove (25A) that has a predetermined depth and is formed on the bottom thereof so that the lock spring for elastically supporting the slide lock is installed in the mounting groove (25A).

Furthermore, the front rail block (20) has groove portions (26) formed by cutting both sides thereof by a predetermined depth to reduce the weight of the front rail block (20) made of a metal material. As illustrated in FIG. 7B, the front rail block (20) has an insertion protrusion (27) that has a predetermined length and protrudes downward from the bottom surface thereof such that the insertion protrusion (27) is inserted into the insertion groove (11C) of the first insertion part (11).

The insertion protrusion (27) has a through-hole (27A) formed in the side surface thereof to communicate with the fastening hole (11C′) of the first insertion part (11).

When the front rail block (20) is inserted into the first insertion part (11) of the frame unit (10) by the structure of the front rail block (20), the front support protrusion (11A) vertically comes into surface contact with the front support part (21) of the front rail block (20) and, at the same time, the rear support protrusions (11B) of the first insertion part (11) come into contact with the rear support part (22) of the front rail block (20), thereby allowing the insertion position of the front rail block (20) to be accurately guided.

Furthermore, a screw, a bolt, or a fastening pin is assembled through the outside of the frame unit (10) such that the insertion protrusion (27) is inserted into the insertion groove (11C) of the first insertion part (11) and then passes through the fastening hole (11C′) and the through-hole (27A) in sequence. Thus, the front rail block (20) inserted into the first insertion part (11) is fixed in the state in which it is in contact with the bottom and front and rear support protrusions (11A and 11B) of the first insertion part (11) so that the first insertion part (11) is tightly assembled to the front rail block (20) without gap therebetween.

The rear rail block (30) is installed in the second insertion part (12) of the frame unit (10). By the rear rail block (30), the slide (2) is slidably assembled while a trigger mechanism housing (not shown) is strongly installed.

In the rear rail block (30), as illustrated in FIGS. 8A and 8B, a first contact part (31) is inclined to come into surface contact with of the inclined contact portion (12A) of the second insertion part (12) while the rear rail block (20) is inserted into the second insertion part (12), and a rear support part (32) has a second contact part (32A) formed at the bottom surface thereof to come into surface contact with the horizontal contact portion (12B) of the second insertion part (12).

A connection portion (33) having an arc shape is spaced at a predetermined distance from the curved portion (12C) of the second insertion part (12), and a third contact part (34) comes into surface contact with the vertical contact portion (12D) while the upper end thereof is connected to the lower end of the connection portion (33).

In addition, a pair of rear rails (35) protrudes from both sides of the rear rail block in opposite directions in the upper portion between the first contact part (31) and the rear support part (32), and each of the rear rails (35) has a horizontal length. The rear rail block has through-holes (36 and 37) formed in the side surfaces thereof at positions corresponding to the pin coupling holes (H1 and H2) of the second insertion part (12).

As illustrated in FIG. 9, when the rear rail block (30) is inserted into the second insertion part (12) of the frame unit (10) by the structure of the rear rail block (30), the insertion position of the rear rail block (30) is accurately guided while the first contact part (31) comes into surface contact with the inclined contact portion (12A) of the second insertion part (12).

When the rear rail block (30) is inserted to a suitable depth, the vertical contact portion (12D) of the second insertion part (12) comes into surface contact with the third contact part (34). As a result, the position of the rear rail block (30), which is inserted along the inclined surface of the first contact part (31) and the vertical surface of the third contact part (34), is naturally fixed as the rear rail block (30) is inserted into the second insertion part (12).

Furthermore, when the rear rail block (30) is sufficiently inserted and reaches a position at which the height of the rear rail block (30) is fixed, the horizontal contact portion (12B) of the second insertion part (12) comes into surface contact with the second contact part (32A) formed at the bottom surface of the rear support part (32) of the rear rail block (30), so that the height of the rear rail block (30) is fixed while the rear rail block is not inserted any more.

As a result, only by the insertion of the rear rail block (30) into the second insertion part (12), the rear rail block (30) is easily installed at an accurate position without movement while the first, second, and third contact parts (31, 32A, and 34) simultaneously come into surface contact with three surfaces having structurally different directions (angles).

In the process of assembling the frame for a pistol with a removable metal rail having the above structure according to an embodiment of the present invention, as illustrated in FIG. 9, the front rail block (20) is inserted into the first insertion part (11) of the frame unit (10) and then the screw, the bolt, or the fastening pin is inserted into the fastening hole (11C′). Thus, the front rail block (20) is fixedly installed in the first insertion part (11) of the frame unit (10).

Next, the rear rail block (30) is inserted into the second insertion part (12), and the coupling pins are inserted into the pin coupling holes (H1 and H2) so that the rear rail block (30) is fixedly installed in the second insertion part (12). In this case, before fixing the rear rail block (30) using the coupling pins, the trigger mechanism housing may be inserted into the second insertion part (12) together with the rear rail block (30) and the rear rail block (30) and the trigger mechanism housing may be simultaneously assembled using the fastening pin.

When each of the front and rear rail blocks (20 and 30) has been assembled to the frame unit (10) as described above, the components such as a barrel, a recoil spring assembly, a trigger, a magazine, and safety pin are sequentially assembled to the frame unit (10). Then, the assembly of the pistol is completed by assembling the slide (1) made of a plastic material onto the frame unit (10) such that the slide is slidable by the front and rear rail blocks (20 and 30), as illustrated in FIG. 10).

Meanwhile, since the frame unit (10) and the front and rear rail blocks (20 and 30) are each made of a metal material in the present invention, it is possible to significantly reduce problems relating to the accidental discharge and malfunction of firearms, a deterioration of accuracy rate, and the like due to thermal deformation. In this case, the front and rear rail blocks (20 and 30) are preferably made of a metal material that is resistant to rust or corrosion.

In accordance with the present invention, a frame for a pistol having a slide made of a plastic material is made of a metal material and the frame is manufactured to be separated into a frame unit and front and rear rail blocks. Therefore, the present invention is advantageous in that each component can be separately replaced as occasion demands.

In addition, the present invention is advantageous in that the front and rear rail blocks are structurally easily and strongly assembled into the first and second insertion parts of the frame unit.

Furthermore, since the front and rear rail blocks are manufactured by cutting a metal material in the form of block, it is possible to secure the accuracy rate and reliability of operation of firearms while preventing the front and rear rail blocks from being easily deformed or damaged even due to external force.

In addition, the front rail block and the rear rail block can be easily and strongly assembled to the first insertion part and the second insertion part of the frame.

While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. 

1. A frame for a pistol with a removable metal rail, a pistol having a slide (1) made of a reinforced plastic material, the frame comprising: a frame unit (10) made of a metal material and having a handle and a first insertion part (11) and a second insertion part (12) formed at its upper portion, the first insertion part (11) and the second insertion part (12) being spaced at a predetermined distance from each other; and a front rail block (20) and a rear rail block (30) made of a metal material and fixedly inserted into the first insertion part (11) and the second insertion part (12), respectively, the slide (1) being slidably assembled to both upper sides of the front rail block (20) and the rear rail block (30), wherein: the first insertion part (11) has an insertion groove (11C) having a predetermined depth, the insertion groove (11C) having a fastening hole (11C′) formed through both sides thereof, wherein the insertion groove (11C) is located at a center of the frame unit (10) in a transverse direction; and the front rail block (20) has an insertion protrusion (27) protruding downward from its bottom surface by a predetermined length such that the insertion protrusion (27) is inserted into the insertion groove (11C), the insertion protrusion (27) having a through-hole (27A) formed through both sides thereof to communicate with the fastening hole (11C′), wherein the insertion protrusion (27) is located at a center of the frame unit (10) in a transverse direction.
 2. The frame for a pistol with a removable metal rail as claimed in claim 1, wherein the second insertion part (12) comprises: an inclined contact portion (12A) that is inclined at a predetermined angle; a horizontal contact portion (12B) that is spaced rearward at a predetermined distance from the inclined contact portion (12A) and has a horizontal surface; a curved portion (12C), the upper end of which is connected to the horizontal contact portion (12B) while the other end thereof is curved downward in an arc form; and a vertical contact portion (12D) having a vertical surface while the upper end thereof is connected to the lower end of the curved portion (12C) wherein: a pair of pin coupling holes (H1 and H2) is formed through both sides of the second insertion part between the inclined contact portion (12A) and the vertical contact portion (12D) and between the inclined contact portion (12A) and the curved portion (12C), respectively.
 3. The frame for a pistol with a removable metal rail as claimed in claim 2, wherein the rear rail block (30) comprises: a first contact part (31) that is inclined to come into surface contact with of the inclined contact portion (12A) of the second insertion part (12) while the rear rail block (20) is inserted into the second insertion part (12); a rear support part (32) that has a second contact part (32A) formed at the bottom surface thereof to come into surface contact with the horizontal contact portion (12B); a connection portion (33) having an arc shape that is spaced at a predetermined distance from the curved portion (12C); a third contact part (34) that comes into surface contact with the vertical contact portion (12D) while the upper end thereof is connected to the lower end of the connection portion (33); and a pair of rear rails (35) that protrudes from both sides of the rear rail block in opposite directions in the upper portion between the first contact part (31) and the rear support part (32), and each of the rear rails (35) has a horizontal length.
 4. The frame for a pistol with a removable metal rail as claimed in claim 1, wherein the front rail block (20) comprises: a front support part (21) that has a vertical surface coming into surface contact with the inside front of the first insertion part (11); a rear support part (22) that has an inclined surface while coming into contact with the inside rear of the first insertion part (11); a pair of front rails (23) that protrudes from both sides of the front rail block in opposite directions in the upper portion between the front support part (21) and the rear support part (22) and each of the front rails (23) has a horizontal length; a slide lock through-hole (24) that is formed through the side surfaces between the rear support part (22) and the front rails (23); and a recoil spring installation groove (25) having a predetermined depth that is formed between the pair of the front rails (23).
 5. The frame for a pistol with a removable metal rail as claimed in claim 1, wherein the front rail block (20) and the rear rail block (30) are made of an aluminum material.
 6. The frame for a pistol with a removable metal rail as claimed in claim 1, wherein the front rail block (20) has groove portions (26) formed by cutting both sides thereof by a predetermined depth to reduce the weight of the front rail block (20).
 7. The frame for a pistol with a removable metal rail as claimed in claim 4, wherein a first slide lock support protrusion (24A) and a second slide lock support protrusion (24B) are formed in the recoil spring installation groove (25), and extend from the slide lock through-hole (24)
 8. The frame for a pistol with a removable metal rail as claimed in claim 7, wherein guide grooves (24A′ and 24B) are formed in the middle portions of the first and the second slide lock support protrusions (24A and 24B), respectively.
 9. The frame for a pistol with a removable metal rail as claimed in claim 1, wherein the first insertion part (11) has only one single insertion groove (11C) and the front rail block has only one single insertion protrusion (27). 